No. of oxalic acid molecules in 100 ml of 0.01 M oxalic acid is -

Options

A. `6.023 times 10^(20)`
B. `6.023 times 10^(21)`
C. ` 6.023 times 10^(22)`
D. `6.023 times 10^(23)`

Answer

To find the number of oxalic acid molecules in 100 ml of a 0.01 M oxalic acid solution, we can follow these steps:

### Step 1: Understand the Molarity Formula
Molarity (M) is defined as the number of moles of solute per liter of solution. The formula is:
\[ M = \frac{\text{Number of moles of solute}}{\text{Volume of solution in liters}} \]

### Step 2: Convert Volume from ml to Liters
We have a volume of 100 ml. To convert this to liters:
\[ \text{Volume in liters} = \frac{100 \text{ ml}}{1000} = 0.1 \text{ L} \]

### Step 3: Calculate the Number of Moles of Oxalic Acid
Using the molarity given (0.01 M), we can find the number of moles of oxalic acid in 0.1 L:
\[ \text{Number of moles} = M \times \text{Volume in liters} \]
\[ \text{Number of moles} = 0.01 \, \text{mol/L} \times 0.1 \, \text{L} = 0.001 \, \text{mol} \]

### Step 4: Use Avogadro's Number to Find the Number of Molecules
Avogadro's number (N_A) is approximately \( 6.022 \times 10^{23} \) molecules/mol. To find the number of molecules, use the formula:
\[ \text{Number of molecules} = \text{Number of moles} \times N_A \]
\[ \text{Number of molecules} = 0.001 \, \text{mol} \times 6.022 \times 10^{23} \, \text{molecules/mol} \]

### Step 5: Calculate the Total Number of Molecules
Now, perform the multiplication:
\[ \text{Number of molecules} = 0.001 \times 6.022 \times 10^{23} = 6.022 \times 10^{20} \, \text{molecules} \]

### Final Answer
The number of oxalic acid molecules in 100 ml of 0.01 M oxalic acid is:
\[ \text{Number of molecules} = 6.022 \times 10^{20} \]

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